Slide rule



NOV. 29, 1949 H 5, UEBERMAN 2.489,79()

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g L w melmagf A -f l INVENTOR. jdfvfg MQeyie @Malfa/L BY 8%? @M Patented Nov. 2 9, 1949 UNITED STATES PATENT OFFICE SLIDE RULE Harry Stanley Lieberman, Evansville, Ind.

Application May 14, 1947, Serial No. 748,018

1 claim. 1

vMy invention relates to improvements in sliderules, such as those used by engineers, architects and draftsmen. Various calculations may -be made mechanically with greater ease and rapidity than by ordinary arithmetical methods, and usually with suflicient accuracy for all practical purposes.

The `usual slide-rule, in its most common form, consists of three main parts. There is a main body or rule, a, slide, and a runner or cursor The accuracy of the results depends on the care with which the user sets the slide. Ihe slides ordinarily do not move too easily and are so constructed that there is considerable friction between the main body and the slide. Although this friction is necessary and is advantageous in maintaining the parts in proper relationship after they are set, it renders a nal perfect adjustment difficult to attain. A rough setting presents no problem, but hair-line accuracy adjustment is a tedious task.

The primary object of my invention is to provide a means on a slide-rule to facilitate a quick and accurate setting of the slide in precise alignment with the main body of the rule.

Another object of my invention is to provide a simple device for securing a fine adjustment on a slide-rule for persons who lack the muscular coordination required to make a setting in the usual way.

A further object of my invention is to provide a simple means for slide adjustment which eliminates the need for gears, racks or other complicated mechanisms.

Yet another object of this invention is to provide an adjustment means for a slide-rule of simple and economical construction which will not require any structural changes of the sliderule itself.

Other objects and advantages of the invention will become apparent from the ensuing description in the course of which reference is had to the accompanying drawings, in which:

Fig. 1 is an elevational View of a standard sliderule showing the adjustment means for the slide;

Fig. 2 is an end elevational view of the sliderule and the slide adjustment;

Fig. 3 is a sectional View taken on line 3--3 of Fig. 1;

Fig. 4 is a, plan view of an end fragment loi. my improved slide-rule;

Fig. 5 is an enlarged fragmentary elevational view showing the construction of the adjustment means; and

Fig. 6 is a modified type of structure.

Referring to Figs. 1 to 5, inclusive, of the single sheet of drawing, the slide-rule is indicated in general by the reference numeral Ill.

The main body l2 has a longitudinal space l4 for receiving the slide I6. Slide-rule lil has the usual runner or cursor I8. At the ends of slide-rule l0 are braces 20 and 22. The widest ends of the braces 20 and 22 are xedly mounted to the main body I2 by rivets 24. The opposite or narrow ends of braces 20 and 22 have an adjustment screw 26, which, under extreme conditions, where shrinkage or swelling becomes so marked as to interfere with the smoothness or operation of the slide, an adjustment can be made.

Mounted and being integral with the upper portions of the braces 20 and 22 are horizontal projecting arms 28, which act as guides or carriers for resilient frictional rollers 30. Rollers 30 have an annular groove 32 for spanning of the tongue 34 on the slide I6. Said annular groove 32 is of suicient depth and Width that it does not interfere or bind with the tongue 34. Rollers 39 have two flat annular faces 3B for frictional contact on both fiat surfaces 38 of the slide I6 and for engagement of the users fingers.

The horizontal projecting arms 28 contain vertical elongated slots 4B for receiving a pin 42 which acts as an axle or trunnion for the rollers 30. Mounted on the pin 42 are a pair of washers 44 for eliminating any undue wear between the rollers 30 and the arms 28. Said elongated slots 40 permit vertical motion when pressure is applied to the rollers 30 by the users iinger, thereby giving a rm, positive contact pressure between the nat faces 36 on the rollers and the flat surfaces 38 of the slide. It can be seen that when securing a rough setting of the slide in the usual manner prior to using rollers 30, there can be no interference or noticeable friction between the rollers 30 and slide I6.

When a fine adjustment is desired, it is apparent that when pressure is applied to the roller 30 by the users finger, the pressure is then transmitted through the roller to the fiat surfaces 38 of the slide l 6 and the minutest movement of the finger will then be translated into a fine hairline adjustment of the slide i6. There being an adjustment roller 30 on each end of the sliderule I0, it is readily apparent that no matter in which direction the slide is moved, one of the roller adjustments may be put in operation.

In the modication illustrated in Fig. 6, at the upper ends of the braces 46, are welded or brazed at 41 a pair of resilient arms 48. Arms 48 carry the rollers 30 by pins 42. When the roller 30 is not beiner urged downwardly, there will be a slight clearance at 59 between the faces 36 of the roller 30 and the flat surfaces 38 of the slide i6. Thus, it can be seen that a slight pressure of the users finger will bend the resilient arms 48, thereby causing immediate contact between the roller 30 and the slide i5.

In conclusion, although my invention has been disclosed in connection with the specific details of preferred embodiments thereof, it must be understocd that such details are not intended to be' limitative of the invention except so far as set" forth in the accompanying claim.

I claim:

In a Sliderule of the character described. and having a slide-rule frame, a tongued slide movable therein, a pair of supporting braces at each end of said frame, the herein improvement which comprises narrow extensions on said. braces, a vertical slot near the outer end of each ei said extensions opposite said braces, axial pins, a silient rotatable member mounted between each pairof extensions on said axial transversing said Vertical slots, said resilient rotatable member having an annular groove on its peripheral edge, whereby said resilient rotatable member is manually adjustable linger-wise with l,said tongued slide in bridged irictional relationship thereto, for moving saidslde relative to said frame.

. y HARRY STANLEY LIEBERMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS OTHER REFERENCES Mechanical lvioverhents,V by Henry T. Brown, published by Brown and Brown in 1879, New Yorks 

